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IC 9071 



Bureau of Mines Information Circular/1986 



/ 



Economic Evaluation of an Electrolytic 
Process To Recover Lead From Scrap 
Batteries 



By Thomas A. Phillips 




UNITED STATES DEPARTMENT OF THE INTERIOR 



Information Circular 9071 



Economic Evaluation of an Electrolytic 
Process To Recover Lead From Scrap 
Batteries 



By Thomas A. Phillips 




UNITED STATES DEPARTMENT OF THE INTERIOR 
Donald Paul Hodel, Secretary 

BUREAU OF MINES 
Robert C. Horton, Director 







^ 



£\b 



n\ 



Library of Congress Cataloging in Publication Data: 



Phillips, Thomas A 

Economic evaluation of an electrolytic process to recover lead from 
scrap batteries. 

(Information circular ; 9071) 

Bibliography: p. 10. 

Supt.ofDocs.no.: 128.27: 9071. 

1. Lead— Electrometallurgy. 2. Lead — Electrometallurgy — Economic 
aspects. 3. Storage batteries— Recycling. 4. Electrolytic cells. I. 
Title. II. Series: Information circular (United States. Bureau of Mines) ; 
9071. 

-T-N-2&&rfcHh- [TN785] 622s [669\4] 85-600314 



CONTENTS 



Page 



Abstract 1 

Introduction 2 

Process and plant description 2 

Feed preparation section 2 

Anode casting section 3 

Leaching section 3 

Electrolysis section A 

Electroref ining A 

Electrowinning A 

Ammonia recovery section 5 

Economics 5 

Capital costs 5 

Operating costs 7 

Products 7 

Profitability 8 

Alternate leach process 9 

Conclusions 10 

References 10 

Appendix A. — Utility requirements, direct labor requirements, major items of 
equipment, daily thermal and utility requirements, and equipment cost 

summaries 11 

Appendix B. — Alternate leach process 18 

ILLUSTRATIONS 

1. Electrolytic process for recovering lead from battery scrap 3 

2. Selling price of lead versus interest rate of return on investment after 

taxes « 9 

TABLES 

1 . Estimated capital cost 6 

2. Estimated annual operating cost 8 

3 . Product values 9 

A-l. Raw material and utility requirements 11 

A-2. Direct labor requirements 11 

A-3. Major items of equipment 12 

A-A. Daily thermal requirements 12 

A-5. Daily utility requirements 12 

A-6. Equipment cost summary, feed preparation section 13 

A-7. Equipment cost summary, anode casting section 1A 

A-8. Equipment cost summary, leaching section 15 

A-9. Equipment cost summary, electrolysis section 16 

A-10. Equipment cost summary, ammonia recovery section 17 

B-l. Estimated capital cost, alternate leach process... 18 

B-2. Estimated annual operating cost, alternate leach process 19 

B-3. Product values , alternate leach process 19 





UNIT OF MEASURE 


ABBREVIATIONS USED 


IN THIS REPORT 


A/m 2 


ampere per square 


meter 


kW'h/lb 


kilowatt hour per pound 


°C 


degree Celsius 






lb 


pound 


cm 


centimeter 






lb/d 


pound per day 


d/wk 


day per week 






lb/h 


pound per hour 


d/yr 


day per year 






ra 


meter 


ft 


foot 






Mgal 


thousand gallon 


ft* 


square foot 






min 


minute 


f t 3 


cubic foot 






MMBtu 


million British thermal unit 


gal 


gallon 






pet 


percent 


g/L 


gram per liter 






st 


short ton 


h 


hour 






st/d 


short ton per day 


h/d 


hour per day 






thm 


therm 


kW 


kilowatt 






V 


volt 


kW»h 


kilowatt hour 






yr 


year 


kW'h/kg 


kilowatt hour per 


ki 


Logram 







ECONOMIC EVALUATION OF AN ELECTROLYTIC PROCESS 
TO RECOVER LEAD FROM SCRAP BATTERIES 

By Thomas A. Phillips ' 



ABSTRACT 

This publication is an economic evaluation of the Bureau of Mines 
electrolytic process for recovering lead from scrap lead-acid batteries. 
In this process, scrap batteries are crushed and separated into metal 
and sludge fractions. The metal fraction is cast as anodes and electro- 
refined. Lead in the sludge fraction is converted to lead carbonate by 
reaction with an ammonium carbonate-ammonium bisulfite solution. The 
lead carbonate is then dissolved in a fluosilicic acid electrolyte from 
which pure lead metal is electrowon. 

A cost estimate is presented for a plant capable of processing 10,000 
scrap batteries per day. The fixed capital cost for this plant is esti- 
mated to be $14 million on a fourth quarter 1984 basis. Operating costs 
are estimated to be $0.15/lb Pb recovered. Assuming a lead selling 
price of $0.17/lb, the interest rate of return on investment after taxes 
is 11 pet. A lead selling price of about $0.21/lb is needed to obtain a 
20-pct-interest rate of return. 



1 Chemical engineer, Avondale Research Center, Bureau of Mines, Avondale, MD. 



INTRODUCTION 



The recovery of secondary lead from scrap is melted and cast as anodes that 



scrap lead-acid batteries currently re- 
quires that the batteries be smelted in 
a furnace. Typically, reverberatory and/ 
or blast furnaces are used. These invar- 
iably release some sulfur dioxide and 
lead fumes to the atmosphere; owing to 
tightening emission and workplace expo- 
sure standards, these emissions are dif- 
ficult to adequately control. 

Researchers at the Bureau of Mines Rol- 
la Research Center have developed alter- 
nate technology to recover lead from bat- 
tery scrap. The metallic portion of the 



are electroref ined. Lead in the battery 
sludge is leached and electrowon by a 
novel technique patented by the Bureau of 
Mines (J_).2 

The technical feasibility of this ap- 
proach has been demonstrated and reported, 
in RI 8602 (2) and RI 8857 (_3 ) . This re- 
port contains an economic evaluation of 
the Bureau's process to aid in assessing 
its potential. Capital and operating 
costs are included for a commercial-scale 
plant based on a conceptual flowsheet de- 
veloped from the Bureau's research. 



PROCESS AND PLANT DESCRIPTION 



In the proposed process, scrap bat- 
teries are crushed and separated into 
four products: Waste sulfuric acid, 
plastic and rubber casing material, me- 
tallic lead, anc 1 a fine sludge. The 
waste acid is neutralized with lime and 
discarded. The plastic casing material 
may have some market potential, and the 
rubber is a waste product. 

The metallic portion of the scrap is 
melted and cast as anodes, which are 
electroref ined using a fluosilicic acid 
electrolyte. Lead in the sludge, as 
either a dioxide or sulfate, is insoluble 
in fluosilicic acid, so it is converted 
to lead carbonate by treatment with a 
solution of ammonium carbonate and ammo- 
nium bisulfite. The lead carbonate is 
then leached with fluosilicic acid to 
produce a solution from which lead is 
electrowon. The major operations are 
shown in figure 1. 

Based on this process, a plant has been 
designed to recover about 82 st/d Pb from 
10,000 scrap batteries. This scale is 
approximately the scale of a large sec- 
ondary smelter. For description, the 
plant has arbitrarily been divided into 
five sections: Feed preparation, anode 
casting, leaching, electrolysis, and am- 
monia recovery. The sizes of the major 
items of equipment for each section are 
shown in table A-3. Daily thermal and 
utility requirements for each section are 
also shown in appendix A. The plant is 
designed to operate 7 d/wk with the feed 



preparation and anode casting sections 
operating one shift and the remainder of 
the plant operating three shifts. 

FEED PREPARATION SECTION 

Scrap batteries are assumed to be de- 
livered to the plant by truck and dumped 
on an acid-proof pad. The batteries are 
picked up by a front-end loader and fed 
to a crushing and classification system. 
This system is available as a packaged 
unit and is capable of classifying bat- 
tery scrap into the proper components. 

In the system, whole batteries are fed 
to a stainless steel hammer mill and 
crushed to a "workable" size. Discharge 
from the hammer mill flows through a se- 
ries of classifiers, which separate the 
scrap into distinct fractions, including 
a metal fraction consisting of grid metal 
and battery posts and a sludge fraction 
of lead sulfate, lead oxide, lead diox- 
ide, and fine metallic lead particles. 
The plastic casing components and hard 
rubber components are also recovered as 
two separate fractions. 

Waste acid from the batteries and water 
used in the classification system are 
collected and mixed with lime to neutral- 
ize the acid. An average acid strength 
of 14 pet l^SO^ is assumed for material 

^Underlined numbers in parentheses re- 
fer to items in the list of references 
preceding the appendixes. 







Li 


me 




Scrap batte 

1 


r ies 




(NH,,) 2 C0 3 

NH,,HS0 3 

solution 


H ? 






NEUTRALIZATION 




FEED PREPARATION 
























Gypsum 








Sludge 




\ 


- 






Metal 1 ic 
lead 






f 








CARBONATE LEACH 


ADSORPTION 










• 

Fi 1 trate 

and 
washi ngs 














f 


1 'nh 3 

C0 2 






MELTING 




w 


1 


, 






' 






< 


1 


an 
wash 


d 




FILTRATION 


AMMONIA RECOVERT 




water 




Waste 








Fine lead 
met a 1 






PbC0 3 


1 






CASTING 




FILTRATION 






I 






Recyc le 
electrodes 




ACID LEACH 




* j| H 2 Sjt- 6 


f 

Gypsum 

e 




Ano 

1 


des 






' 










~~t ' 






Fi Iter 




FILTRATION 




aid 




1 

Recyc le e lect rol y t 










' 




L 




Makeup electrolyte 












■ r 










' 






ELECTRO-REFINING 




' ELECTROLYTE FILTRATION 




ELECTROWINNING 




f V 

t imo 
lime 
















< 
Lead r 


letal An 
s 


5 










\ 
Lead 


1 
met a 1 







FIGURE 1. - Electrolytic process for recovering lead from battery scrap. 



balance calculations , although it may 
vary from 4 to 20 pet. The neutralized 
slurry flows to a pond, where the solids 
settle. Periodically the pond is dredged 
to remove the solids for disposal. Over- 
flow from the pond is pumped through a 
sand filter for reuse in the process or 
discharge to a sewer. 

ANODE CASTING SECTION 

Metal from the feed preparation section 
is fed to a melting furnace along with 
recycled anodes from electroref ining and 
fine lead prills recycled from the leach- 
ing section. Upon melting, a slag forms 
from the oxidized portion of the feed, 
protecting the molten lead from further 
oxidation. (A portion of the slag is 
periodically skimmed from the furnace, 
allowed to cool, and discarded.) Molten 
lead from the casting furnace is poured 
into molds, forming the anodes. Each 
anode is approximately 0.75 m by 1.5 m by 
1 cm. These are arbitrary dimensions. 



LEACHING SECTION 

Sludge from the feed preparation sec- 
tion is mixed with an ammonium carbonate- 
ammonium bisulfite solution and heated to 
55° C. Average retention in the carbon- 
ate leach is 1 h. During this time, the 
following reactions are assumed to take 
place: 

PbSO^ + (NH 1+ ) 2 C0 3 * PbC0 3 + (NH 1+ ) 2 SO t+ 

and Pb0 2 + NH^HS0 3 + (NH^) 2 C0 3 

■*■ PbC0 3 + (NH 1+ ) 2 S0 1+ + NH^OH. 

The lead carbonate formed is insoluble 
and is recovered and washed on a rotary- 
vacuum drum filter. A filter aid is re- 
quired to give adequate filtration rates. 
Both filtrate and washings are pumped to 
the ammonia recovery section. 

To dissolve the lead carbonate, the 
filter cake is mixed with recycled 
fluosilicic acid electrolyte from the 



electrolysis section. The electrolyte 
initially contains about 120 g/L free 
H 2 SiF 6 and about 50 to 70 g/L Pb as 
PbSiF 6 . Leaching at 45° C for 30 min in- 
creases the lead content of the electro- 
lyte to about 100 g/L. The primary leach 
reaction is assumed to be 

PbC0 3 + H 2 SiF 6 ■> PbSiF 6 + H 2 + C0 2 . 

Unreacted solids, primarily metallic 
lead, lead sulfate, and some phosphate 
compounds, are mixed with additional fil- 
ter aid and separated from the loaded 
electrolyte in a rotary— vacuum drum fil- 
ter. The filter cake is discharged to a 
screen, and much of the metallic lead is 
separated for recycle to the anode cast- 
ing section. Solids passing the screen 
are allowed to dewater and then col- 
lected for disposal. These solids are 
stable and can be discarded in a land- 
fill. Loaded electrolyte from the filter 
is pumped to the electrolysis section. 

ELECTROLYSIS SECTION 

Elect roref ining 

Anodes from the anode casting section 
are placed in electroref ining cells. It 
is assumed that 30 anodes will be refined 
per cell. Cathodes are 0.16-cm-thick 
lead starter sheets. Spacing between 
electrodes is 3 cm. The electrolyte is 
fluosilicic acid, which flows by gravity 
from a head tank through the electro- 
refining cells to a sump. From the sump 
the electrolyte is pumped up through a 
clarifying filter to the head tank. 
Makeup electrolyte is taken from the 
electrowinning circuit. 

Anodes are pulled from the cells every 
3 days to remove the slime blanket that 
forms. This slime contains 70 pet Sb, 
11 pet Pb, less than 5 pet As, less than 
1 pet Sn, and less than 0.1 pet Ag. It 
is assumed that the slime can be sold to 
recover these metal values. 

When 60 pet of the anode is consumed, 
it is pulled from the refining cell and 
returned to the anode casting section to 
be remelted and recast as an anode. Cur- 
rent density in the cell is about 170 
A/m 2 at a cell voltage of 0.3 V. Average 



current efficiency in laboratory studies 
was about 98 pet with an average power 
consumption of 0.09 kW*h/kg Pb recovered. 
The cathode lead assays 99.99 pet Pb. 

Electrowinning 

Loaded electrolyte from the leaching 
section is fed to a head tank from which 
it flows to the electrowinning cells. 
These cells are identical to the electro- 
refining cells with the exception of the 
anode, which is titanium coated with in- 
soluble lead dioxide. The anode was de- 
veloped and patented (4_) at the Bureau's 
Rolla Research Center. Cell voltage is 
maintained at 2.5 V with a current den- 
sity of 170 A/m 2 . 

During electrowinning about one-third 
of the lead in solution is reduced. The 
cell reaction is assumed to be 

2PbSiF 6 + 2H 2 -► 2Pb + 2H 2 SiF 6 + 2 . 

Normally the reaction would be 

2PbSiF 6 + 2H 2 + Pb + Pb0 2 + 2H 2 SiF 6 . 

The presence of phosphate in the electro- 
lyte (found normally in byproduct fluo- 
silicic acid) seems to favor the first 
reaction. Over 99 pet of the lead re- 
acted is recovered as metallic lead at 
the cathode. The small quantity of lead 
recovered as Pb0 2 at the anode is recy- 
cled to the carbonate leach. Current ef- 
ficiencies are 95 pet or better with 
overall power consumption of 0.8 kW-h/kg 
Pb recovered. 

The lead remaining (about 70 g/L) in 
the electrolyte forms a recirculating 
load in the acid leach-electrowinning 
circuit. Reducing a higher percentage of 
lead would reduce current efficiencies. 

Spent electrolyte flows from the elec- 
trowinning cells to a sump from which it 
is returned to the leaching section. In 
the test work to date impurity buildup 
has not been a problem. Some electrolyte 
will be lost to the acid leach residue 
and other causes such as drag out. Make- 
up fluosilicic acid should be byproduct 
acid from the manufacture of phosphate 
fertilizer to take advantage of its natu- 
ral phosphate content. 



AMMONIA RECOVERY SECTION 

Leachate from the ammoniacal treatment 
contains ammonium carbonate, ammonium 
sulfate, and some ammonium hydroxide. 
This stream is mixed with lime and fed to 
a steam stripping tower. The lime ties 
up the sulfate ions, freeing the ammonia, 
which is pulled off the tower as a vapor. 
The ammonium carbonate decomposes and 
leaves the tower as ammonia and carbon 



dioxide. Gypsum formed in the stripping 
tower is separated from the remaining so- 
lution by filtration. 

Filtrate from the gypsum filter is used 
to absorb the ammonia and carbon dioxide 
gases from the stripping. Makeup ammonia 
and carbon dioxide are also absorbed in 
this step. Sulfur dioxide is then bub- 
bled through this solution to produce 
ammonium bisulfite for the recycle leach 
solution. 



ECONOMICS 



The intent of an economic evaluation 
is to present a capital and operating 
cost estimate of a commercial-size plant. 
Such estimates may be used as an aid for 
studies and decisions on the course of 
future research. 

In the preparation of any economic 
evaluation, it is necessary to make many 
assumptions. In general, the assumptions 
that are made are expected either to 
apply to the majority of the potential 
plants or to have only a small effect on 
the process capital and operating costs. 
An example of such an assumption in this 
report is that most of the plant operates 
three shifts per day, 7 d/wk. 

However, if an assumption is neces- 
sary that may not apply to a majority of 
plants and that may have a major effect 
on capital or operating costs, then the 
assumption is generally excluded from the 
evaluation. An example of such an exclu- 
sion is that land cost has not been in- 
cluded in the capital or operating cost 
estimates. When an assumption has been 
made or when it has been deliberately ex- 
cluded, this fact is documented in the 
report. 

• Because of the large number of assump- 
tions necessarily present in its economic 
evaluations, the Bureau strives to pre- 
sent its evaluations in a format suf- 
ficiently detailed and flexible to al- 
low a user to make any adjustments that 
would fit the evaluation to a particular 
situation. 

CAPITAL COSTS 

The capital cost estimate is of the 
general type called a study estimate by 



Weaver and Bauman (5_) . This type of es- 
timate, prepared from a flowsheet and a 
minimum of equipment data, can be ex- 
pected to be within 30 pet of the actual 
cost for the plant described. The esti- 
mated fixed capital cost on a fourth 
quarter 1984 basis (Marshall and Swift 
(M and S) index of 785.2) for a plant 
processing 10,000 batteries per day is 
about $14 million, as shown in table 1. 
Based on an average production of 164,000 
lb/d Pb, this translates to a capital in- 
vestment of $0.26 per annual pound. 

Equipment costs for the process are 
based on cost-capacity data and manufac- 
turers' cost quotations. Exceptions are 
the electroref ining and electrowinning 
cells. These have been hand designed and 
costed based on commercial electroref in- 
ing and electrowinning cell designs. 
Equipment costs for each section are 
shown in tables A-6 through A-10. Cost 
data are brought up to date by the use 
of inflation indexes. In developing the 
plant capital costs, corrosion-resistant 
materials of construction were used where 
appropriate. For example, the leach 
tanks are steel, lined with polyester, 
and acid-resistant brick. 

Factors for piping, etc. , except for 
the foundation and electrical factors, 
are assigned to each section, using as a 
basis the effect fluids, solids, or a 
combination of fluids and solids may have 
on the process equipment. The founda- 
tion cost is estimated for each piece of 
equipment individually, and a factor for 
the entire section is calculated from the 
totals. The electrical factor is based 
on motor horsepower requirements for each 
section. A factor of 10 pet, referred to 



TABLE 1. - Estimated capital cost 1 



Fixed capital: 

Feed preparation section $1,767,800 

Anode casting section 1 ,567 ,800 

Leaching section 1 ,776,300 

Electrolysis section 4,650,700 

Ammonia recovery section 453 ,000 

Steamplant 94,900 

Subtotal 10,310,500 

Plant facilities, 10 pet of above subtotal 1,031,100 

Plant utilities, 12 pet of above subtotal 1,237,300 

Basic plant cost 12,578,900 

Escalation costs during construction 483,300 

Total plant cost 13,062,200 

Land cos t 

Subtotal % 13,062,200 

Interest during construction period 1 ,007 ,100 

Fixed capital cost 14,069,300 

Working capital: 

Raw material and supplies 300,000 

Product and in-process inventory 673,300 

Accounts receivable 673,300 

Available cash 493,700 

Working capital cost 2,140,300 

Capitalized startup costs 140,700 

Subtotal 2,281,000 

Total capital cost 16,350,300 

1 Basis: M and S equipment cost index of 785.2. 

as miscellaneous, is added to each sec- labor for auxiliary buildings such as of- 

tion to cover minor equipment and con- f ices , shops, laboratories, and cafete- 

struction costs that are not shown with rias , and the cost of nonprocess equip- 

the equipment listed. ment such as office furniture, together 

For each section, the field indi- with safety, shop, and laboratory equip- 

rect cost, which covers field supervi- ment. Also included are labor and mate- 

sion, inspection, temporary construction, rial costs for site preparation such as 

equipment rental, and payroll overhead, site clearing, grading, drainage, roads, 

is estimated at 10 pet of the direct and fences. The cost of water, power, 

cost. Engineering cost is estimated at and steam distribution systems is in- 

5 pet, and administration and overhead eluded under plant utilities, 

cost is estimated at 5 pet of the con- Inflation during construction can be a 

struction cost. A contingency allowance major economic factor; therefore, an es- 

of 10 pet and a contractor's fee of 5 pet timation of the effects of inflation is 

are included in the section cost. included as escalation costs during con- 

The costs of plant facilities and plant struction. An expenditure schedule based 

utilities are estimated as 10 and 12 pet, on the basic plant cost is adjusted on a 

respectively, of the total process sec- monthly basis to obtain the escalation 

tion costs and include the same field cost. Over a construction period of 18 

indirect costs, engineering, administra- months the inflation rate is assumed to 

tion and overhead, contingency allowance, be constant at 5 pet annually, 

and contractor's fee as are included in The cost for interest on the capital 

the section costs. Included under plant borrowed for construction is included as 

facilities are the costs of material and interest during construction. A simple 



annual interest rate of 10 pet has been 
assumed. The same expenditure schedule 
used to calculate escalation costs during 
construction is used to adjust the inter- 
est rate over the construction period. 
Land investment is not included in this 
estimate. Cost for the plant owner's su- 
pervision is not included in the capital 
cost of the processed plant. 

Working capital is defined as the funds 
in addition to fixed capital, land in- 
vestment, and startup costs that must be 
provided to operate the plant. Working 
capital, also shown in table 1, is esti- 
mated from the following items: (1) Raw 
material and supplies inventory (cost of 
raw material and operating supplies for 
30 days), (2) product and in-process in- 
ventory (total operating cost for 30 
days), (3) accounts receivable (total op- 
erating cost for 30 days) , and (4) avail- 
able cash (direct expenses for 30 days) . 

Capitalized startup costs are estimated 
as 1 pet of the fixed capital, which is 
shown in table 1 . 

OPERATING COSTS 

The estimated operating costs are based 
on 330 d/yr operation over the life of 
the plant. This allows 35 d/yr downtime 
for inspection, maintenance, and unsched- 
uled interruptions. The operating costs 
are divided into direct, indirect, and 
fixed costs. 

Direct costs include raw materials, 
utilities, direct labor, plant mainte- 
nance, payroll overhead, and operating 
supplies. The raw material costs do not 
include transportation costs. Electric- 
ity, water, and natural gas are purchased 
utilities. Raw material and utility re- 
quirements per pound of lead are shown in 
table A-l. 

Direct labor costs are estimated on the 
basis of assigning 4.2 employees to each 
position that operates 24 h/d, 7 d/wk, 
and 1.4 employees to each position that 
operates 8 h/d, 7 d/wk. Sectional labor 
requirements are shown in table A-2. The 
cost of labor supervision is estimated as 
15 pet of the labor cost. 

Plant maintenance is separately esti- 
mated for each piece of equipment and for 



the buildings, electrical system, piping, 
plant utility distribution systems, and 
plant facilities. 

Payroll overhead, estimated as 35 pet 
of direct labor and maintenance labor, 
includes vacation, sick leave, Social 
Security, and fringe benefits. The cost 
of operating supplies is estimated as 20 
pet of the cost of plant maintenance. 

Indirect costs are estimated as 40 
pet of the direct labor and maintenance 
costs. The indirect costs include the 
expenses of control laboratories, ac- 
counting, plant protection and safety, 
plant administration, marketing, and com- 
pany overhead. Research and overall com- 
pany administrative costs outside the 
plant are not included. 

Fixed costs include the cost of taxes 
(excluding income taxes), insurance, and 
depreciation. The annual costs of both 
taxes and insurance are each estimated as 
1 pet of the plant construction cost. 
Depreciation is based on a straight-line, 
10-yr period. 

The estimated annual operating cost for 
the proposed plant is about $8.2 million, 
as shown in table 2. Based on a produc- 
tion of 164,380 lb/d Pb, 330 d/yr, this 
corresponds to a cost of $0.15/lb Pb. 

PRODUCTS 

Products from the proposed process in- 
clude 164,380 lb/d Pb and 5,832 lb/d Sb 
slimes. In addition, about 60,000 lb/d 
plastic and rubber will be recovered. 
Between 56,400 and 83,300 lb/d byproduct 
gypsum will be recovered depending on 
the strength of the waste battery acid. 
At an average of 14 pet H^SO^ the quan- 
tity of gypsum will be 73,230 lb. About 
22,000 lb/d residue from the acid leach 
step is also recovered. 

The lead, antimony slimes, and plastic 
products should be marketable. Both the 
byproduct gypsum and the leach residue 
will be relatively stable waste products, 
which can be disposed of in a landfill. 
The rubber recovered will probably be 
considered a hazardous waste and will 
have to be handled as such. Product val- 
ues or disposal costs are shown in ta- 
ble 3. The assumed disposal cost for 



TABLE 2. - Estimated annual operating cost 



Annual 


Cost per 


cost 


pound lead 


$2,348,800 


$0,043 


373,400 


.007 


29,100 


.001 


283,000 


.005 


264,700 


.005 


82,400 


.002 


120,800 


.002 


1,700 


1.000 


11,800 


1.000 


700 


1.000 


3,516,400 


.065 


512,100 


.009 


4,900 


1.000 


201,600 


.004 


718,600 


.013 


542,900 


.010 


81,400 


.002 


624,300 


.012 


303,600 


.006 


60,700 


.001 


303,500 


.006 


667,800 


.013 


346,000 


.006 


133,600 


.002 


6,006,700 


.114 


516,800 


.010 


130,600 


.002 


130,600 


.002 


1,406,900 


.026 


8,191,600 


.151 



Direct cost: 
Raw materials: 

Whole batteries at $50/st 

Fluosilicic acid at $92/st 

Ammonia at $ 2 1 0/ s t 

Carbon dioxide at $90/st , 

Sulfur dioxide at $210/st . .... 

Filter aid at $150/st 

Lime at $30.75/st 

Glue at $0.85/lb 

Calcium lignin sulfonate at $0.25/lb 

Chemicals for steamplant water treatment 

Total 

Utilities: 

Electric power at $0.047/kW«h 

Process water at $0.25/Mgal 

Natural gas at $4.50/MMBtu 

Total 

Direct labor: 

Labor at $9/h , 

Supervision, 5 pet of labor 

Total. 

Plant maintenance: 

Labor 

Supervision, 20 pet of maintenance labor 

Materials 

Total 

Payroll overhead, 35 pet of above payroll 

Operating supplies, 20 pet of plant maintenance.... 

Total direct cost 

Indirect cost, 40 pet of direct labor and maintenance 
Fixed cost: 

Taxes, 1 pet of total plant cost 

Insurance, 1 pet of total plant cost 

Depreciation, 10-yr life 

Total operating cost 

1 Numbers have been rounded down to $0,000. 



gypsum and leach residues is a compro- 
mise between typical costs for urban and 
rural disposal. The values used for the 
lead and plastic products are based on 
published prices for competitive mate- 
rials (i.e., primary lead and plastic 
resins) . 

PROFITABILITY 

Based on the estimated operating cost 
and the projected product values, the in- 
terest rate of return on investment after 



taxes is 11 pet, using the interest rate 
of return method for calculations. Nor- 
mally, consideration of a new project 
would require a 15-pct rate of return on 
investment after taxes as a minimum. 
This preceding calculation is based on 
the March 1985 lead price of $0.17/lb. 
Secondary lead is listed at $0.21/lb. 
Based on this value, the interest rate of 
return on investment after taxes is 20 
pet. Since the price of lead is not sta- 
ble at the moment, figure 2 is presented 
to show how the estimated interest rate 



TABLE 3. - Product values 





Daily 
production 


Estimated 
unit value 


Annual returns 
(debits) on sales 


Value per pound 
lead product 


Products: 


164,380 lb 

5,832 lb 

54,000 lb 


$0.17/lb 
.58/lb 
,05/lb 


$9,222,000 

1,116,000 

891,000 


$0.17 




.021 
.016 




NAp 


NAp 


11,229,000 


.207 


Waste products: 


36.6 st 
11.2 st 

3.0 st 


-10.00/st 

-10.00/st 

-100.00/st 


-121,000 
-37,000 
-99,000 


-.002 




-.001 
-.002 




NAp 


NAp 


-257,000 


-.005 




NAp 


NAp 


10,972,000 


.202 



NAp Not applicable. 

^otal daily production of plastic and rubber 
values, the plastic product is estimated to be 
rubber is estimated to be 10 pet. 



is 60,000 lb. To compute product 
90 pet of the total and the waste 



of return on investment after taxes will 
change with changing lead prices. In- 
cluded in the rate of return calculations 
are the revenues (debits) for the poten- 
tial byproducts, as shown in table 3. 

ALTERNATE LEACH PROCESS 

To date, the main emphasis of the Bu- 
reau's research has been to develop a 
process to efficiently extract lead from 
battery scrap as pure metal. One pro- 
posed alternative would be to change the 
leach procedure. Only the lead sul- 
fate would be leached, leaving the lead 
dioxide in the leach residue. The leach 



S 25 


1 1 


1 1 


o 






Q 
< 






LU 












U. 






o „„ 






LU 20 




^s^ — 


o 






tr 






Q. 






o 






z 






_j 






_j 






W ^ 


1 I 


I i 



5 10 15 20 25 3i 

INTEREST RATE OF RETURN ON INVESTMENT AFTER TAXES, pet 

FIGURE 2. - Selling price of lead versus interest 
rate of return on investment after taxes. 



residue would then be sold to a lead 
smelter for its lead content. 

The advantage of this flowsheet is that 
the leach-electrowinning circuit would 
be simplified. Less ammonium carbonate 
leach solution is required, and the need 
for ammonium bisulfite is eliminated. 
Less lead will be electrowon; therefore, 
the electrowinning circuit is smaller. 
Ammonia recovery equipment is also 
smaller as less ammonia has to be circu- 
lated. Since electroref ining requires 
less energy than electrowinning, electri- 
cal energy requirements are reduced from 
0.20 kW-h/lb to 0.178 kW'h/lb Pb. 

The Bureau has not investigated the 
alternate process and has no actual data 
to verify that these advantages will be 
realized. For this reason, a detailed 
cost evaluation of this process is not 
presented. It is possible, however, to 
project costs for a hypothetical process 
assuming that only the outlined changes 
occur without any additional complica- 
tions. All costs presented are intended 
to indicate what the potential of this 
process may be, and any comparison to 
the original process has to be qualified 
owing to the lack of supportive data 
available. 

Fixed capital costs for the alternate 
leach process are reduced about $1.3 mil- 
lion, or 9 pet. Operating costs per unit 
of recovered lead are increased about 1.3 



10 



pet, or $0.002/ lb Pb recovered. Byprod- 
uct credits, however, for this process 
are much higher (table B-3) . This re- 
sults in an estimated interest rate of 
return on investment after taxes of 15.4 
pet with a lead price of $0.17/lb. At 
$0.21/lb Pb, the interest rate of return 



on investment will be 25 pet. Thus, the 
alternate leach process appears to have 
more economic potential, if a market for 
the leach residue is available. Capital 
and operating costs for this process are 
presented in tables B-l and B-2. 



CONCLUSIONS 



1. The fixed capital cost for a plant 
sized to process 10,000 scrap batteries 
per day is estimated to be about $14 mil- 
lion based on fourth quarter 1984 equip- 
ment costs. 



2. The estimated operating cost for 
this plant is $0.15/lb Pb recovered. 

3. At a selling price of $0.17/lb, the 
interest rate of return on investment af- 
ter taxes is calculated to be 11 pet. 



REFERENCES 



1. Cole, E. R. , Jr., A. Y. Lee, and 
D. L. Paulson. Electrowinning of Lead 
From H 2 SiF 6 Solution. U.S. Pat. 
4,272,340, Jan. 9, 1981. 

2. . Electrolytic Method of Re- 
covery of Lead From Scrap Batteries. Bu- 
Mines RI 8602, 1981, 19 pp. 

3. Lee, A. Y. , E. R. Cole, Jr., 
and D. L. Paulson. Electrolytic Method 
of Recovery of Lead From Scrap Bat- 
teries, Scale-up Study Using 20-Liter 



Multielectrode 
1984, 20 pp. 

4. Smith, L. 
E. R. Cole, Jr 
Lead Dioxide 
4,159,231, June 

5. Weaver, J 
Cost and Profi 
25 in Perry's 
book, ed. by R. 
ton. McGraw-Hi 



Cell. BuMines RI 8857, 

L., R. G. Sandberg, and 
Method, of Producing a 
Coated Anode. U.S. Pat. 
16, 1979. 
B . , and H . C . Bauman . 
tability Estimation. Sec. 
Chemical Engineer's Hand- 
H. Perry and C. H. Chil- 
li, 5th ed., 1973, p. 47. 



11 



APPENDIX A. — UTILITY REQUIREMENTS, DIRECT LABOR REQUIREMENTS, 

MAJOR ITEMS OF EQUIPMENT, DAILY THERMAL AND UTILITY 

REQUIREMENTS, AND EQUIPMENT COST SUMMARIES 



Raw material and utility requirements 
per pound of lead are shown in table A-l. 
The labor requirements and the major 
items of equipment for each section are 
shown in tables A-2 and A-3, respec- 
tively. Daily thermal and utility 



requirements for each section are shown 
in tables A-4 and A-5, respectively. The 
equipment cost summaries for each section 
in the process are contained in tables 
A-6 to A-10. 



TABLE A-l. - Raw material and utility requirements 



Raw materials, lb: 

Whole batteries 

Fluosilicic acid 

Ammonia 

Carbon dioxide 

Sulfur dioxide 

Filter aid. . . . « 

Lime 

Glue 

Calcium lignin sulfonate 

Utilities: 

Electric power kW*h. . 

Process water gal. . 

Natural gas thm. . 



Quantity per 
pound lead 

1.732 
.150 
.005 
.116 
.046 
.020 
.145 
.000 
.001 

.201 
.365 
.083 



TABLE A-2. - Direct labor requirements, 
operators per shift 



Section 



Shifts per week 



21 



2 14 



35 



Feed preparation 

Anode casting 

Electrolysis 

Ammonia recovery 

Steamplant 

Total 

*3 shifts per day, 7 d/wk. 
2 2 shifts per day, 7 d/wk. 
3 1 shift per day, 5 d/wk. 



0.0 


2.5 
.5 
1 



4.0 



12 



TABLE A-3. - Major items of equipment 



Section and equipment 




Size 



Feed preparation 
Anode casting: 

Melting furnace 

Anode casting wheel...... 

Leaching: 

Carbonate leach tank. 

Carbonate leach filter... 

Acid leach tank 

Acid leach filters 

Electrolysis: 

Electroref ining cells.... 

Melting furnace 

Casting machine 

Electrowinning cells 

Rectifier 

Ammonia recovery section: 

Bubble tank 

2-effect evaporator 

Rotary-vacuum drum filter 



Reclamation system. 



1,800 batteries per hour, 

135 ft 3 . 

15 anodes per hour. 

1,200 gal. 
250 ft 2 . 
6,000 gal. 
400 ft 2 . 

175 lb/h. 
550 ft 3 . 
100 ft long. 
300 lb/h. 
1,600 kW. 

1,800 gal. 

144 ft 2 per effect. 

50 ft 2 . 



TABLE A-4. - Daily thermal requirements 



Section and item 



Steam, 
MMBtu 



Natural gas , 
MMBtu 



Anode casting: Melting furnace 
Leaching: 

Carbonate leach tank 

Acid leach tank 

Subtotal 

Electrolysis: Melting furnace. 
Ammonia recovery: Evaporator.. 

General plant 

Total process requirements 

Steamplant 

Grand total 



0.00 



7.00 
8.60 



15.60 



.00 

33.20 

.00 



48.80 
■48.80 



.00 



11.28 



.00 
.00 



.00 



9.53 

.00 
17.00 



37.81 
97.92 



135.73 



TABLE A-5. - Daily utility requirements 



Section and major process water consumer 



Electric 1 power, 
kW'h 



Process water, 
Mgal 



Feed preparation: Reclamation system. 

Section total , 

Anode casting , 

Leaching: 

Carbonate leach filter 

Acid leach filters 

Section total 

Electrolysis 

Ammonia recovery: Bubble tank , 

Section total 

Steamplant 

General plant 

Plant total 



NAp 

1,380 

247 

NAp 

NAp 

1,801 

22,496 

NAp 

369 

115 

6,610 



9 


.5 


9 


.5 


.0 


4 

1 


.7 

.7 


6 


.4 


.0 


37 


.8 


37 


8 



33,018 



5.1 



.0 



59.5 



NAp Not applicable. 

1 Individual electric power consumers not shown; only major process water consumer shown. 



13 



TABLE A-6. - Equipment cost summary, feed preparation section 

Item Equipment 1 Labor Total 



Belt conveyor, 
Belt conveyor, 
Lime storage. 
Screw feeder. , 
Slurry tank.. 

Pumps 

Storage tanks, 

Pump 

Sand filter. . 
Holding tank. 



$17,800 


$5,100 


$22,900 


20,200 


5,800 


26,000 


11,400 


3,000 


14,400 


2,300 


500 


2,800 


1,500 


700 


2,200 


1,900 


1,100 


3,000 


15,900 


4,100 


20,000 


1,700 


1,000 


2,700 


41,300 


1,500 


42,800 


21,100 


8,900 


30,000 



Total 135,100 31,700 166,800 

Reclamation system 2 910, 600 

Front-end loader 39,700 

Total equipment cost x factor indicated: 

Foundations, x 0.511 69,100 

Structures, x 0.070 9,500 

Instrumentation, x 0.050 6,800 

Electrical, x 0.142 19,100 

Piping, x 0.200 27 ,000 

Painting, x 0.020 2,700 

Miscellaneous, x 0.100 13,500 

Total 147,700 

Total direct cost 1,264,800 

Field indirect, 10 pet of total direct cost 126,500 

Total construction cost 1,391,300 

Engineering, 5 pet of total construction cost 69,600 

Administration and overhead, 5 pet of total construction cost 69,600 

Subtotal 1,530,500 

Contingency, 10 pet of above subtotal 153, 100 

Subtotal 1,683,600 

Contractor's fee, 5 pet of above subtotal 84,200 

Section cost 1,767,800 

^•Basis: M and S equipment cost index of 785.2. 
2 Installed cost. 



14 



TABLE A-7. - Equipment cost summary, anode casting section 

Item Equipment 1 Labor Total 



Surge bin $5,600 $1,500 $7 

Apron feeder 8,200 1,600 9 



Melting furnace 244,900 9,500 254 

Bag dust collector 28 , 400 500 28 

Anode casting wheel 208,400 19,000 227 



$5,600 


$1,500 


8,200 


1,600 


244,900 


9,500 


28,400 


500 


208,400 


19,000 



Total 495,500 32,100 527 

Slag mold 2 1 

Straddle carrier 2 264 

Forklift trucks 30 



Total equipment cost x factor indicated: 

Foundations, x 0.083 41 

Buildings, x 0.079 39 

Structures , x 0.050 24 

Instrumentation, x 0.100 49 

Electrical, x 0.018 9 

Piping, x 0.150 74 

Painting, x 0.020 9 

Miscellaneous, x 0.100 49 



Total 297 



Total direct cost 1,121 

Field indirect, 10 pet of total direct cost 112 

Total construction cost 1,234 

Engineering, 5 pet of total construction cost 61 

Administration and overhead, 5 pet of total construction cost 61 



Subtotal 1,357 

Contingency, 10 pet of above subtotal 135 



Subtotal 1 , 493 

Contractor's fee, 5 pet of above subtotal 74 



Section cost 1,567 



1 Basis: M and S equipment cost index of 785.2. 
2 Installed cost. 



100 
800 
400 
900 
400 



600 
300 
800 
500 



300 
000 
800 
600 
100 
300 
900 
600 



600 



800 
200 



000 
700 
700 



400 
700 



100 
700 



800 



15 

TABLE A-8. - Equipment cost summary, leaching section 

Item Equipment 1 Labor Total 

Sludge bin $6,000 $1,600 $7,600 

Screw feeder 2,300 500 2,800 

Carbonate leach tank 7,000 2,100 9,100 

Carbonate leach filter 89,800 12,000 101,800 

Pump 1,500 700 2,200 

Belt conveyor 5,800 1,500 7,300 

Bucket elevator 6,000 2,200 8,200 

Acid leach tank 50,300 4,800 55,100 

Acid holding tank 28,700 4,100 32,800 

Pump 5,300 700 6,000 

Vibrating screen 8,700 1,400 10,100 

Hopper 300 100 400 

Acid leach filters 367,300 24,500 391,800 

Belt conveyor 19,100 4,800 23,900 

Pump 4,900 1,000 5,900 

Total 603,000 62,000 665,000 

Total equipment cost x factor indicated: 

Foundations, x 0.114 68,600 

Buildings, x 0.237 164,700 

Structures, x 0.090 54,300 

Instrumentation, x 0.100 60,300 

Electrical, x 0.058 34,900 

Piping, x 0.250 150,800 

Painting, x 0.020 12, 100 

Miscellaneous , x 0. 100 60,300 

Total 606,000 

Total direct cost 1,271,000 

Field indirect, 10 pet of total direct cost 127,100 

Total construction cost 1,398,100 

Engineering, 5 pet of total construction cost 69,900 

Administration and overhead, 5 pet of total construction cost 69 ,900 

Subtotal 1,537,900 

Contingency, 10 pet of above subtotal 153,800 

Subtotal 1 , 691 , 700 

Contractor's fee, 5 pet of above subtotal 84,600 

Section cost 1,776,300 

1 Basis: M and S equipment cost index of 785.2. 



16 



TABLE A-9. - Equipment cost summary, electrolysis section 

Item Equipment 1 Labor Total 



Bridge crane $88,000 $4,600 $92 

Electrolyte head tank 19,300 4,000 23 

Electrorefining cells 180,100 39,900 220 

Melting furnace 123,000 17,100 140 

Casting machine 179,400 28,500 207 

Sumps 7,900 6,200 14 



Pumps 9,200 2,600 11 

Electrowinning cells 245,600 22,600 268 

Sumps 9,000 8,200 17 

Pumps 15,300 3,700 19 

Recycle tank 27,800 4,100 31 

Pump 3,600 1,200 4 

Starter sheet preparation 54,600 19,000 73 



$88,000 


$4,600 


19,300 


4,000 


180,100 


39,900 


123,000 


17,100 


179,400 


28,500 


7,900 


6,200 


9,200 


2,600 


245,600 


22,600 


9,000 


8,200 


15,300 


3,700 


27,800 


4,100 


3,600 


1,200 


54,600 


19,000 



Total 962,800 161,700 1,124 

Rectifier 2 353 



Total equipment cost x factor indicated: 

Foundations, x 0.130 125 

Buildings, x 0.886 852 

Structures, x 0.070 67 

Insulation, x 0.030 28 

Instrumentation, x 0.100 96 

Electrical, x 0.235 226 

Piping, x 0.350 337 

Painting, x 0.020 19 

Miscellaneous , x 0. 100 96 



Total 1 , 849 



Total direct cost 3,327 

Field indirect, 10 pet of total direct cost 332 



Total construction cost 3,660 

Engineering, 5 pet of total construction cost 183 

Administration and overhead, 5 pet of total construction cost 183 



Subtotal 4,026 

Contingency , 10 pet of above subtotal 402 



Subtotal 4,429 

Contractor's fee, 5 pet of above subtotal 221 



Section cost 4,650 



1 Basis: M and S equipment cost index of 785.2. 
2 Installed cost. 



600 
300 
000 
100 
900 
100 
800 
200 
200 
000 
900 
800 
600 



500 
500 



600 
900 
400 
900 
300 
000 
000 
300 
300 



700 



700 
800 



500 
000 
000 



500 
700 



200 
500 



700 



17 



$5,400 


$2,500 


27,200 


3,600 


2,400 


400 


1,900 


700 


2,000 


600 


2,300 


500 


1,300 


800 


27,300 


15,000 


9,900 


1,500 


51,200 


6,800 


200 


600 


1,300 


700 


15,400 


4,800 



TABLE A-10. - Equipment cost summary, ammonia recovery section 

Item Equipment 1 Labor Total 

Bubble tank 

Vent scrubber 

Pump 

Mixing tank 

Storage bin 

Screw feeder 

Pump 

2 -effect evaporator 

Pumps 

Rotary— vacuum drum filter 

St orage tank 

Pump 

Belt conveyor 

Total 147 ,800 38,500 

Total equipment cost x factor indicated: 

Foundations , x 0.080 

Structures , x 0.070 

Instrumentation, x 0.100 

Electrical, x 0.163 

Piping, x 0.400 

Painting, x 0.020 

Miscellaneous, x 0.100 

Total 

Total direct cost 

Field indirect, 10 pet of total direct cost 

Total construction cost 

Engineering, 5 pet of total construction cost 

Administration and overhead, 5 pet of total construction cost 

Subtotal 

Contingency, 10 pet of above subtotal 

Subtotal 

Contractor's fee, 5 pet of above subtotal.. 

Section cost 

1 Basis: M and S equipment cost index of 785.2. 



$7 


900 


30 


,800 


2 


,800 


2 


,600 


2 


,600 


2 


,800 


2 


,100 


42 


300 


11 


,400 


58 


,000 




800 


2 


,000 


20 


,200 


186 


,300 


11 


,800 


10 


,300 


14 


800 


24 


,100 


59 


,100 


3 


,000 


14 


800 


137 


900 


324 


200 


32 


,400 


356 


,600 


17 


,800 


17 


,800 


392, 


200 


39 


,200 


431 


,400 


21 


600 


453 


000 



18 



APPENDIX B. —ALTERNATE LEACH PROCESS 

The estimated capital cost and the an- and B-2, respectively. Table B-3 shows 
nual operating cost, for the alternate product values, 
leach process, are shown in tables B-l 

TABLE B-l. - Estimated capital cost, 1 alternate leach process 

Fixed capital: 

Feed preparation section $1,767,800 

Anode casting section 1 , 567 ,800 

Leaching section 1,252,400 

Electrolysis section 4,176,700 

Ammonia recovery section 511, 100 

Steamplant 94,900 

Subtotal 9 , 370 , 700 

Plant facilities, 10 pet of above subtotal 937,100 

Plant utilities, 12 pet of above subtotal 1, 124,500 

Basic plant cost 11,432,300 

Escalation costs during construction 439,200 

Total plant cost 11,871,500 

Land cost 

Subtotal 1 1 , 87 1 , 500 

Interest during construction period 915,300 

Fixed capital cost 12,786,800 

Working capital: 

Raw material and supplies 258,700 

Product and in-process inventory 602 , 200 

Accounts receivable 602,200 

Available cash 437,100 

Working capital cost 1,900,200 

Capitalized startup costs 127,900 

Subtotal 2,028,100 

Total capital c ost 14,814,900 

1 Basis: M and S equipment cost index of 785.2. 



TABLE B-2. - Estimated annual operating cost, alternate leach process 



19 



Annual 


Cost per 


cost 


pound lead 


$2,348,800 


$0,049 


373,400 


.008 


10,000 


i.OOO 


110,400 


.002 


82,400 


.002 


87,000 


.002 


1,700 


1 .000 


11,800 


.001 


700 


i.OOO 


3,026,200 


.064 


399,900 


.008 


3,900 


i.OOO 


199,900 


.004 


603,700 


.012 


542,900 


.011 


81,400 


.002 


624,300 


.013 


276,100 


.006 


55,200 


.001 


276,200 


.006 


607,500 


.013 


334,500 


.007 


121,500 


.003 


5,317,700 


.112 


492,700 


.010 


118,700 


.002 


118,700 


.002 


1,278,700 


.027 


7,326,500 


.153 



Direct cost: 
Raw materials: 

Whole batteries at $50/st 

Fluosilicic acid at $92/st 

Ammonia at $210/st 

Carbon dioxide at $90/st 

Filter aid at $150/st 

Lime at $30.75/st 

Glue at $0.85/lb 

Calcium lignin sulfonate at $0.25/lb 

Chemicals for steamplant water treatment 

Total 

Utilities: 

Electric power at $0.047/kW«h 

Process water at $0.25/Mgal 

Natural gas at $4.50/MMBtu 

Total 

Direct labor: 

Labor at $9/h 

Supervision, 15 pet of labor 

Total 

Plant maintenance: 

Labor 

Supervision, 20 pet of maintenance labor 

Materials 

Total 

Payroll overhead, 35 pet of above payroll 

Operating supplies, 20 pet of plant maintenance.... 

Total direct cost 

Indirect cost, 40 pet of direct labor and maintenance 
Fixed cost: 

Taxes, 1 pet of total plant cost 

Insurance, 1 pet of total plant cost 

Depreciation, 10-yr life 

Total operating cost 

lumbers have been rounded down to $0,000. 



TABLE B-3. Product values, alternate leach process 





Daily 
production 


Estimated 
unit value 


Annual returns 
(debits) on sales 


Value per pound 
lead product 


Products: 


144,890 lb 

39,840 lb 

5,832 lb 

54,000 lb 


$0.17/lb 
.07/lb 
.58/lb 
.05/lb 


$8,128,000 

960,000 

1,116,000 

891,000 


$0.17 




.02 
.023 




.019 




NAp 


NAp 


11,095,000 


.232 


Waste products: 


28.6 st 
3.0 st 


-10.00/st 
-100.00/st 


-94,000 
-99,000 


-.002 




-.002 


Subtotal 


NAp 


NAp 


-183,000 


-.004 








NAp 


NAp 


10,912,000 


.228 



NAp Not applicable. 

^otal daily production of plastic and 
the plastic product is estimated to be 90 
mated to be 10 pet. 

U.S. GOVERNMENT PRINTING OFFICE: 1986—605-017/40,016 



rubber is 60,000 lb. To compute product values, 
pet of this total and the waste rubber is esti- 

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Pittsburgh. Pa. 15236 



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